Airway Management Flashcards
What is the acceptable extubation failure rate?
10-20%
An re-intubation rate < 10 may indicate too conservative as approach
A re-intubation rate > 20 may indicate premature extubations
What are the criteria for weaning and extubating a patient?
A - patent. If in doubt check for cuff leak or look down.
B - minimal oxygenation supporr FiO2 < 0.4, PEEP < 8, adequate ventilatory drive, ability to clear secretions
C - haemodynamic stability
D - sufficient consciousness to protect airway
E - original pathology resolved, no impending procedures under GA/sedation
What factors suggest failure of a spontaneous breathing trial?
Physiological Hr > 20% increase or > 140 SBP > 20% baseline or >180/<90 Cardiac arrhythmias Resp rate > 50% BASELINE OR > 35 pAo2 < 8 ON fIo2 >0.5 pAco2 >6.5 pH < 7.32 Clinical Agitation or anxiety Depressed mental state Sweating/cyanosis Increased resp effort
What are the risk factors for failing extubation?
Age > 65 Underlying chronic cardiorespiratory disease Heart failure / LV dysfunction COPD OSA/obesity PaCO2 > 6.5 Neuromuscular disorders Positive fluid balance Ventilation > 6 days
How many ICU patients experience post extubation stridor? What are the risk factors?
16% Female Muscle weakness Tracheal infection TRacheal stenosis Recent airway surgery Intubation > 36 hours Excessive cuff pressures Large ETT Aggressive suctioning NGT insertion
What are the indications for tracheostomy in ICU patients?
Inability to maintain upper airway - primary pathology or neurological impairment
Prolonged ventolator wean
Inability to adequately clear secretions
What are the potential advantages of trache over ETT?
Shorter tube - reduced dead space, reduced resistance to gas flow, reduced work of breathing, easier access for suctioning
Reduced need for sedation - improved cough and secretion clearance, improved communication, better compliance with physio
Avoidance of ETT - better mouth care, potential for speech, potential to eat
What are the contra-indications for tracheostomy?
Local - anatomical abnormalities, infection over insertion site, known or suspected difficult ETT, short neck, obesity, unstable spinal injury
Systemic - coagulopathy, significant haemodynamic instbaility, significant resp support (FiO2 >0.6, PEEP >10), inability to tolerate changes in PaCO2 (e.g. raised ICP)
What are the complications of a tracheostomy?
Immediate - hypoxia, hypercarbia, loss of airway, aspiration, haemorrhage, damage to local structures, anaesthesia related e.g. anaphylaxis, hypotension
Early - infection, displacement with loss of airway, occlusion, tracheal injury, haemorrhage (mucosal injury or erosion into right brachiocephalic artery)
Late - tracheal dilatation, tracheomalacia, tracheal stenosis
What are the indications for bronchoscopy?
Diagnostic - broncho-alveolar lavage, biopsy, assessment of inhalational injury, confirm ETT position
Therapeutic- removal of bronchial obstruction, placement of bronchial stent
Assist invervention - FOI, perc trache, DLT insertion, positioning of endobronchial blocker
What is ARDS?
An inflammatory process affecting the lungs
Initial injury precipitates a sequence of events manifesting as impaired oxygenation, impaired compliance and increased dead space
It has 3 phases - exudative, proliferative, and fibrosing
What is the definition of ARDS?
Defined by the Berlin criteria
Timing - Occurs within 1 week of a known clinical insult
Chest imaging - bilateral opacities on CXR
Origin of oedema - resp failure not fully explained by cardiac failure or fluid overload
Moderate-to-severe hypoxia - defined by the PaO2/FiO2 ratio on a ventilator with >5cmh2o PEEP.
p:f < 39.9 > 26.6 = mild
p:f < 26.6 > 13.3 = moderate
p:f < 13.3 = severe
What is the differential diagnosis of ARDS?
Cardiogenic pulmonary oedema
Acute eosinophilic pneuimonia
Cryptogenic organizing pneumonia
Diffuse alveolar haemorrhage
What is the aetiology of ARDS?
Direct - pnuemonia, viral pnuemonitis, chemical pnuemonitis, smoke inhalation, near drowning, pulmonary contusions, reperfusion injury, thoracic radiation
Indirect - systemic sepsis, major trauma, pancreatitis, pregnancy-related, TRALI, tumour lysis syndrome
What are the general management strategies for ARDS?
Sedation - improves mechanical ventilation compliance and decreases O2 consumption
Neuromuscular blockade -improves compliance and decreases O2 consumption - not without complication - but there is evidence that they may decrease mortality if used early on in severe ARDS
Fluid balance - conservative strategy leads to improved lung function and reduced number of days on the ventilator but no decrease in mortality
House-keeping - infection control, DVT prophylaxis, Ulcer prophylaxis and nutrition
